Kata Contacts

Pedro V. Gómez Sánchez - [email protected] - @pedro_g_s - github.com/pedrovgs

Karumi Dojo: Kata ContactsPedro Vicente Gómez SánchezSenior Mobile Developer at Karumi

[email protected]@pedro_g_sgithub.com/pedrovgs

mailto:[email protected]


Sergio GutierrezSenior Mobile Developer

Alberto GrageraTechnical Director

Jorge BarrosoGoogle Developer Expert

Davide MendoliaSenior Full Stack Engineer



Karumi Dojo● We are here to practice and learn.

● This exercise is meant to be collaborative, not competitive.

● Try to open your mind to new concepts.



Karumi Dojo● We are here to practice architecture.

● Keep always in mind the S.O.L.I.D principles.

● We are going to practice pair programming.



Clean Architecture



Clean Architecture Principles

● Separation of concerns using layers.

● Independent of Framework or third party libraries.

● Testable.

● Independent of UI or Database.

● The Dependency Rule.



Clean Architecture Principles

● Entities representing enterprise business rules.

● Use cases of the software.

● Adapters to be decoupled from boundaries.

● Platform/Framework as a delivery mechanism.

● Data mapping.



Clean Architecture Conclusion

“Conforming to these simple rules is not hard, and will save you a lot of headaches going forward. By separating the software into layers, and conforming to The Dependency Rule, you will create a system that is intrinsically testable, with all the benefits that implies. When any of the external parts of the system become obsolete, like the database, or the web framework, you can replace those obsolete elements with a minimum of fuss.” - Robert C. Martin



Clean Architecture Karumi Style



Clean Architecture Karumi Style

● Model View Presenter and Presentation Models.

● Use cases

● Repositories to abstract the data origin.

● Adapters to abstract third party libraries.

● Data mapping.



Time to practice!!!



Rules:● Do not start coding until you understand the requirements.

● Do not start coding without thinking in the most important part of the domain.

● Today your notebook is more important than your laptop.

● Think carefully the patterns and responsibilities associated to every class.



Tips● Baby steps.

● Think before to code.

● Write always testable code.



Kata Contacts● Command line application to handle your agenda.

● All the data is local but in the future will consume an external API.

● The user can add a contact.

● The user can list all the contacts already added.



Are you ready?



Business Requirements



Entities



Data Storage



Use Cases



User Interface



Changing Requirements



Testing



Resources

● The Clean Architecture - Robert C. Martin

● Kata Contacts - Karumi

● Rosie - Karumi


https://blog.8thlight.com/uncle-bob/2012/08/13/the-clean-architecture.html

https://blog.8thlight.com/uncle-bob/2012/08/13/the-clean-architecture.html

https://github.com/Karumi/KataContactsJava

https://github.com/Karumi/KataContactsJava

https://github.com/Karumi/Rosie

https://github.com/Karumi/Rosie

Kata Contacts

Engineering

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